Organization and Homeostasis Human Body Organization and Homeostasis

Determined to be different Cells do not begin their life as a heart, liver, skin, or stomach cell (etc.) In the beginning, cells have the potential to become any of the 200 different cell types after going through the processes of determination and differentiation After these processes the cell becomes specialized in a specific function, specialized cells are the first level of organization. determination occurs within the first few weeks of zygote division where most stem cells become committed to develop into only one type of cell, still have the info just lose the ability to express it Differentiation-committed cells acquire the structures and functions of highly specialized cells, occurs because specific genes are turned on

Cell Differentiation

Specialization Each type of specialized cell has a particular structure to perform a specific task The specialization of cells leads to the 11 major organ systems within your body

Levels of organization 28.1

Homeostasis 28.2 It is important for the systems in your body to maintain balance The body can do so by sending feedback between systems You have sensors in your skin, blood vessels, and of course the brain that allow signals to be sent and read to aid in processes such as thermoregulation

Feed back mechanisms Positive feedback Negative Feedback a response that causes a change to continue in the same direction, does not result in homeostasis Examples: childbirth, blood clotting Negative Feedback a response that reverses the change in order to restore homeostasis Examples: thermoregulation, blood sugar regulation

Disrupting Homeostasis 28.3 Each system can affect the others through feedback If drastic changes occur in one system such as Failure to detect changes Wrong messages sent Serious injuries Viruses or bacteria Then what starts in one system can trigger a domino affect and cause both short and long term effects

Exit ticket 1) Name one fact you know about the human body. 2) What would you like to learn more about?